Tank Cleaning and Sludge Handling Equipment
Over the years NESL have perfected the equipment required to move vast quantities of sludge.
Today we have a range of specialist equipment available.
NESL Mover (Sit & Ride Dozer)
Zero-man entry for tank cleaning operations is rapidly becoming standard practice in all European Countries. The Mover system however is still the fastest way to clean large diameter crude tanks where limited man entry is permitted.
The mover system comprises four major components.
The Mover Vehicle
The Hydraulic Power Pack
The Reels complete with Umbilical
The Lobe pump
The mover, lobe pump and umbilical are all certified for use in a zone 1 area (ATEX Group II Cat 2) and the power pack is certified for use in a zone 2 area (ATEX Group II Cat 3).
The second option is a remotely operated dozer controlled by an operator outside of the tank.
The ROV is best suited to tanks with no heating coils where zero-man entry is permitted. The ROV comes with an insertion ramp which is slid into the 24” manway. No men are required to enter the tank for insertion or removal of the ROV from the tank and the ROV is simply driven up the ramp and into the tank. Once inside the tank, the ramp can be removed and a supplied roller is placed in the manway to aid the movement of the umbilical through the manway.
The ROV is certified for use in a Zone 1 area (ATEX Group II Cat 2) and the unit includes an anti-static umbilical for extra protection. All electrical components are EX certified and all fluid path material is stainless steel.
The NESL Tanksweep system is designed for the de-sludging of petroleum & chemical storage tank by the control and circulation of high velocity liquid streams through directable nozzles fitted to the tank shell. Depending on the size of the tank and the product stored up to four sets of tank sweeps might be required with each of them where possible spaced evenly around the tank perimeter. The tanksweeps are all a standard length but where space is restricted a more compact version is available.
Each system is comprised the following major components:
Tank Sweep Unit
Centrifugal Pump Unit
Hydraulic Jacking Pump
Each Tanksweep is capable of a throughput of six hundred and sixty cubic meters per hour when used in conjunction with the NES 500D at a pressure of ten bar and has a sweep angle of two hundred degrees.
The NES 500D pump unit is certified for use in areas classified as a Zone II. Each unit is fitted with automatic shutdown protection including a gas detector, chalwyn valve, and spark arrestor.
The success of NES Tanksweeps used on problem tanks where the sludge level was above the manways and required a hot-tap to insert Tanksweep has led to the development of the fixed Tanksweep.
NES Fixed Tanksweeps are for use in new tanks or tanks that have been cleaned and are about to be put back into service. Alternatively, they can be used on tanks where the manway can be removed for cleaning and used to re-suspend accumulated solids enabling the tank to be pumped down with a maximum contents removal effected without man entry.
Fixed Tanksweeps are simple to install by using the existing manways and can be connected to the tank operators own pumps and existing pipework.
The number of tanksweeps required depends on the tank diameter. Typically 2 Tanksweeps are required for tanks up to 50m in diameter, 3 Tanksweeps are required for tanks with diameters between 50m and 80m, and 4 Tanksweeps are required where the tank has a diameter greater than 80m.
Tanksweeps will prevent a build-up of sludge on the tank floor by creating a movement in the oil inside the tank. This movement ensures that any solids are suspended in the mobile oil and do not settle on the tank floor.
Tanksweep nozzles can be rotated 200 degrees either manually from the outside of the tank by means of a hand wheel, or the unit can be hydraulically controlled.
Zero-man entry for tank cleaning & de-sludging operations is rapidly becoming standard practice in all European countries as well as elsewhere. NESL has developed the Manway Cannon for zero entry cleaning operations.
The latest generation of systems come completely installed inside a modified 20-foot standard ISO container divided into two compartments. The first compartment houses the control room that is fully lined and insulated and comes with a combined heating/air conditioning unit. Within the control room are all the controls necessary for controlling the equipment. The second compartment houses the electro-hydraulic power unit permanently installed along with stacked reels for umbilical storage. Manway cannon units and smart nozzles where required are door mounted on lift out storage frames for ease of deployment.
MOVCAN - ROV Tracked Cannon
This system is available as an add-on for the Manway Cannon system or as a containerized stand-alone system.
The MovCan utilises a combination of the Manway Cannon system and the Mover. Our standard range of ROV's come with a slightly smaller track base which allows for remote insertion into a tank whereas the MovCan comes with the larger, more powerful, mover track.
The MovCan requires a minimum of 2 persons to enter the tank in order to assemble the unit. Assembly is carried out right by the manway and takes approximately 20 minutes.
Once built, the operation of the MovCan is carried out from the Manway Cannon system control desk.
NESL Weir Tanks
When using any jetting system for the cleaning of large diameter storage tanks the required amount of jetting media can be greatly reduced by using a re-circulation system. We designed the NESL Weir Tank System to work solely with the NESL Cannon System and reduce the waste produced during any tank cleaning operation.
Built into an ISO 20’ standard shipping container and divided into four compartments comprising of one control/pump room and three individual tanks. The control area houses all controls for the system which can be run either from this control area or remotely from a Manway Cannon control desk. It also contains valves for modifying fluid path inside the container, pumps, blowers, electrical control panels, and lighting.
All equipment contained in the container is certified for use in a zone 1 area (ATEX Group II Cat 2). Power is supplied to the unit from a customer supplied source. The unit comes equipped with level control and automatic shutdown systems. A small compartment is built into the side of the container. This area contains the level transmitters, alarms and sounders. With the weir tank system, a combination of alarms is incorporated into the design whereby both flashing lights and audible alarms are used.
ATC Mud Cannon
ATC Tank Cleaning System (ATC) comprises three main elements:
The wash system incorporates an operator control station, a jetting pump, smart nozzle and the umbilical which reaches between the ATC and the nozzle head.
The recovery system comprises a vacuum truck which has been fitted with a modified top manway hatch which has a floating suction installed, and the vacuum hoses between the PSV tank and the vacuum truck
The separation process starts in the vacuum truck, where the liquid and solid portions of the recovered waste are separated, and extends into the ATC where the fluids are transferred through a filtration system into the wash fluid reservoir using one of the jetting pumps. Within the wash fluid reservoir a further separation takes places using a top weir and surface skimming system to remove the oil element of the liquid transferred from the vacuum tanker.